Studies on the conformational stability of the triple-stranded collagen polypeptide chain and on side-chain-backbone interactions will be continued from the previous year of the grant. In the past studies, the conformational freedom of side-chains was assessed, and the extend of distortion of the triple helix was estimated as a function of amino acid sequence. In the proposed work, a newly developed model of hydration will be applied to the collagen peptides studied before, in order to assess the modifications induced by water upon conformational behavior. Computational methods will be developed to treat side-chain interactions between neighboring triple-stranded helices in the absence and presence of water. The packing of triple strands and their longitudinal alignment is to be studied, using theoretical methods. Conformational studies will be carried out on bends and related local folding patterns in proteins.